The present invention refers to means for burning liquid fuels of the hing having a tendency to cause deposits in conduits and fixtures, and where there are seasons to fear operational disturbances caused by such deposits. Such fuels are for instance found among the waste liquors produced when pulping wood.
When burning sulphite liquor from the magnesium or calcium process in recovery furnaces two separate supply conduit systems are usually provided for feeding the burners, one of said conduits being used to transport the waste liquor, while the other is washed by a fluid (usually acid water). After a certain period of time (usually 8 hours) the two systems are switched over in such a manner that the liquor in the first system is substituted by washing fluid, and the washing fluid in the second system is substituted by liquor.
This is necessary in order to prevent the formation of such thick deposits, which would be the result if one conduit was used to transport liquor for too long a time. At each burner there is branch conduit, which is connectable to both main conduits and may be switched over to the main contuit occassionally supplying liquor while being disconnected to the conduit transporting washing fluid.
In order to wash the branch conduit as well as the burner connected thereto it has hitherto been necessary to disconnect the burner, to remove the lance body and to substitute the latter by a fitting connected to a hose, which in turn is connected to a return flow conduit. Thereafter the washing fluid is made to flow through the burner head and the branch conduit to the return flow conduit. The system including the branch conduit and the burner head is usually washed during 8 hours. With a furnace provided with twelve burners it is common praxis to disconnect two burners simultaneously, which means that each burner will operate for two days between washings. During such a period the deposits formed will build up to such amounts that they will noticeably reduce the free flow area and thus also the capacity of the burner. It is evident that the lance body may easily be substituted by a clean one at any time.